Hi guys I want to 3d my ultimate.. They call for a .70 size four stroke max in this plane.. But reading reviews on this plane they say more power is needed. The plane is going to weigh around 6.5 lbs... I want plenty of power to hover.... Would a .90 size four stroke be to much??? What motor size shuold I be looking at??? Carl from Michigan

Great Planes is conservative with their engine recommendations because guys try to claim a structure malfuction under warranty when they bolt a larger engine on the front. That is just Great Plane's defense. So if you want to go larger just make sure the firewall is well glued any maybe add some tri-stock and/or fiberglass cloth. Just be sure it is WELL GLUED. I guess this is a kit so you are doing the gluing anyway.

I would think a Saito .82 or even their .91 would be a nice power source for this model. With the .91 you would probably need a 15x4 prop for 3D so make sure the ground clearance of a 15" prop is enough for you.

I should add....... to prevent aileron flutter you should upgrade to 4-40 control rods between the wings and be sure to seal any gaps. There have been some complaints about flutter with this model. Some guys have criticized me for providing this recommendation, but if I am going to express my opinion that it is OK to go with a higher than "allowed" engine I am going to say go heavy duty to fix a possible problem area that could end your project in a hurry........... Good luck.

I just got the GP Ultimate 160 version and total weight after build and radio gear in was 15 LBS now GP recomends a fuji 43 cc gas as a max , But I went ahead and put a DA50 on her instead , I also want to coution you if your GP is a arf be very carefull about what size engine you use , When I got mine last month its says only 20 hrs to complete, well needless to say it took me about a month , Why? becouse I stripped it down and recovered it to a scale sheme (tired of all the Ultimates looking the same) Lol Lol Anyway after stripping it down I found 22 spots on the fuse and the wings that didnt even get glued , after fixing them and going over the rest of the plane with a fine tooth comb this is what I ended up with and man can she fly , Ive got the CG right where GP recomends and all the throws on minimin and she 3 D's like no one ever saw. Good luck in your project , Grant it not everyone will go through there ARF like I did But good luck just the same.

I run mine with a Saito .82 and 3 blade 13-8 prop. pictures in my gallery. it has power galore. It will hover and torque roll but it could use a bigger diameter lower pitch prop for the low speed high alpha stuff. The Saito .82 weighs about the same as a .40 and is the same size. and sips the gas so you can run a smaller tank to save weight. $259 at advantage hobby. I have seen them on sale for less. Great flying plane BTW.